The present invention refers to a method and a device for the removal of total cholesterol, low density lipoprotein cholesterol (LDL) and/or high density lipoprotein cholesterol (HDL) from whole blood. In particular, the device comprises means for separating blood plasma from red blood cells from said whole blood.
Plasmapheresis is a common medical procedure whereby plasma is separated from whole blood. It has been used to treat patients suffering from various chronic illnesses involving an exchange of volume of 2.5 L or more. Taking into consideration the large volume, when using plasmapheresis to treat medical conditions once the plasma is separated from the whole blood, the blood can be returned to the body with replacement fluids, such as fresh plasma and/or an albumin solution. Plasmapheresis has also been used for the purpose of obtain human plasma donations. In these cases, the volume extracted is no larger than 880 mLs, and the blood can be returned with or without replacement fluids.
When treating patients with therapeutic plasmapheresis, a catheter is placed in a large vein, such as in the arm, and a second catheter is placed in another vein, such as a vein in the foot or hand. Blood then passes out of the body via the catheter and through a separator. Plasma is separated from the whole blood. The blood without plasma the desired fluids and optional replacement fluids can be returned to the body via the second catheter. For plasma donations, however, automated plasmapheresis equipment is used where a single venipuncture is required, as the blood is removed and returned through the same site.
There are several different types of therapeutic plasmapheresis including: (i) plasma exchange in which plasma that is separated and discarded is replaced with fresh plasma or an albumin solution, (ii) double filtration plasmapheresis in which plasma is passed through a separator with a small pore size so as to selectively remove large molecular weight proteins, or (iii) plasma adsorption in which plasma flows into a plasma adsorption column wherein certain substances can be adsorbed and removed. Plasmapheresis used for plasma donations, however, uses mostly centrifugation (e.g., Haemonetics blood processing systems) or centrifugation with a simple filter (e.g, Fenwal blood processing systems).
It is known to use low-density lipoprotein therapeutic apheresis to treat patients suffering from familial hypercholesterolemia. Evans, Katie D., “Low-Density Lipoprotein Apheresis in Patients with Severe Familial Hypercholesterolemia Refractory to, or Intolerant of, Lipid-Lowering Drug Therapy: Preventing the Onset or Progression of Cardiovascular Disease” (2011). School of Physician Assistant Studies. Paper 268. Such studies have used low-density lipoprotein (LDL) apheresis as an adjunct to lipid-lowering drugs, and the apheresis is administered once every one to three weeks. Id at 10. However, reduction in LDL levels is typically accompanied by reduction in high-density lipoprotein (HDL) levels to varying degrees. Id at 9. Such an effect can be undesirable particularly in patients having borderline and/or low HDL levels.
As discussed in Yokoyama, S. et al., “Selective Removal of Low Density Lipoprotein by Plasmapheresis in Familial Hypercholesterolemia”, (1985). Artheriosclerosis Vol. 5, No. 6, pp. 613-622. Therapeutic plasmaphereis was performed on patients using hollow-fiber membrane filters or selective adsorption of very low density lipoproteins to selectively remove LDL. Id. at 613. It was determined that membrane-filter plasma separators are not suitable for hyperchylomicronemic patients. Id a 616. While LDL levels were reduced, there was no statistically significant change in HDL levels and slight over-recoveries of HDL was attributed to reconcentration of the plasma. Id at 619.
A treatment regime in which periodic plasmapheresis, requiring smaller volumes than traditional therapeutic plasmapheresis, shorter duration time and a single venipuncture that reduces LDL levels in patients having abnormal LDL levels and/or increases HDL levels in patients having abnormal HDL levels would be desirable.